Scientists seek land to burn for a good cause
Scion fire scientists Shana Gross and Hugh Wallace are on a mission - to burn your gorse and raze your wilding pines, all in the name of scientific research.
But Gross and Wallace, fire experts at Scion, the Crown Research Institute for forestry and wood processing, haven’t been having much luck finding a farmer with patches that need clearing.
Speaking with Stuff, Wallace said their hunt for thick gorse on a slope or dense wilding pines on flat ground as potential research burn sites had so far come up blank.
While they initially thought there would be hundreds of farmers who would dearly love to be rid of their pest vegetation, leads have come up as dry as the gorse they hope to ignite.
“People have been so aggressive over the last 10 years clearing land. We had this huge laundry list - people were like ‘call this guy’,” Wallace said.
“We called him and he cleared it last year. Then it’s ‘what about this guy?’ He cleared it two years ago. Everyone’s got the same idea at the same time.”
Gross said they were looking for multiple blocks that were 200 metres by 200m, and while logistically the South Island would be easier, they wouldn’t be ruling out the north.
Their research, once they find a suitable piece of land, will be looking into convective fire spread, the “very fundamentals of how fire spreads and behaves”, Wallace said.
“This is a really basic idea. You’ve got fire in one spot, how does it move to another? That hasn't really been effectively studied anywhere in the world.”
Carried out in conjunction with the US Forest Service San José and the University of Canterbury, their most recent site in Twizel, ironically, was burnt down in a wildfire.
One of the interesting discoveries that burn produced, Wallace said, was that even a gentle fire did a good job of killing wilding seedlings.
Using cutting edge instrumentation, their large scale research burns include the placement of hundreds of heat resistant thermometers, sensors that manage wind speeds and air pressure, weather stations, and 30-60m tall masts with sonic anemometers - high speed, very sensitive wind speed and direction sensors.
Their research is timely, as according to the institute, the direct cost of wildfire on New Zealand’s economy in 2020 was $142 million. By 2050, this was predicted to soar to $547m annually, because of global warming.
Wallace said climate change was increasing both the frequency and severity of wildfires and escalating the risks, not just in rural areas like Tasman’s Lee Valley where fire recently broke out, but also where people felt more secure, such as the edges of cities in the rural-urban interface.
This trend was more advanced overseas, where fires were burning into cities across the globe, such as fires that burnt more than 15,000 homes in Valparaiso and Viña del Mar in Chile at the start of February.
“As wildfire researchers, we know that fire conditions are worsening, and there are more and more extreme fire days each year,” he said.
“While this year started relatively slowly, we are starting to see a steady string of wildfires across New Zealand.”
El Niño was causing sustained warm, dry winds, adding to the usual hot and dry summer weather, conditions that quickly sucked the moisture out of plants, leaving them ready to burn only hours after rain.
Fortunately, New Zealand’s maritime climate meant that it hadn’t been hit as quickly as other areas, Gross said, giving the country the opportunity to learn and better prepare.
Wildfires are high on the radar of those living in the top of the south, where the largest fire since 1955 at the time hit Pigeon Valley in 2019, burning through 2300 hectares with a perimeter of 35 kilometres.
Not all fires were bad, Gross said, but people needed to be aware of fire weather